Extinction risks and threats to our freshwater fish

Update 12 December 2023:

An IUCN Press Release on their updated red list’ says: 

The Atlantic salmon (Salmo salar) has moved from Least Concern to Near Threatened, with new evidence showing the global population decreased by 23% between 2006 and 2020’.

The EA have also just published the 2022 statistics for salmon and sea trout populations in England and Wales. See our News Item on this topic for key figures and links to the full stats. 

News item 28 November 2023: 

Up until now, there has not been a formal assessment of the extinction risks of freshwater fish in Britain and this has impeded their inclusion in relevant legislation and policy.

A recent study published in Aquatic Conservation, has identified 7 species threatened with extinction at the regional level: 

  • European eel (Anguilla anguilla) and allis shad (Alosa alosa) are classified as Critically Endangered.
  • Atlantic salmon (Salmo salar), vendace (Coregonus albula) and European whitefish (Coregonus lavaretus) are classified as Endangered.
  • Arctic charr (Salvelinus alpinus) and twaite shad (Alosa fallax) are classified as Vulnerable.

The study used the International Union for the Conservation of Nature (IUCN) Red List of Threatened Species™ Categories and Criteria to make the assessment.

Our study outlines, species by species, the evidence for their declines and the threats they face. This can be used to inform what actions should be taken to preserve and restore these populations and the important river and lake habitats they rely on


Brown trout (Salmo trutta) is categorised as Least Concern’. However, Salmo trutta includes both resident trout and sea trout.
Evidence presented at the recent Sea Trout Symposium held in Cardiff in September 2023 was clear: over the last decade, sea trout numbers have plummeted in rivers throughout England, Wales, Scotland and Ireland. Barriers to migration, poor water quality, predation, marine exploitation and climate change were identified as the main causes. 

Alosa alosa
Allis shad. (Wikipedia).